The principle of the see-saw is well-known, in which two children sit at opposite ends of a beam, and the beam pivots for up/down movement about a fulcrum mounted on a support post. The invention combines the use of the basic see-saw idea with an adjustable mechanism to create a teaching/learning apparatus, in which children use their own physical bodies to help them acquire abstract concepts in mathematics and physics. Using their own bodies provides young children with a powerful bridge to fundamental abstract concepts in mathematics and physics, such as numerically-balanced equations, addition, leverage, and moment force.